ports/sysdeps/alpha/fpu/fesetenv.c

   1 /* Install given floating-point environment.
   2    Copyright (C) 1997-2014 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Richard Henderson <rth@tamu.edu>, 1997
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library.  If not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <fenv_libc.h>
  21
  22 int
  23 __fesetenv (const fenv_t *envp)
  24 {
  25   unsigned long int fpcr;
  26   fenv_t env;
  27
  28   /* Magic encoding of default values: high bit set (never possible for a
  29      user-space address) is not indirect.  And we don't even have to get
  30      rid of it since we mask things around just below.  */
  31   if ((long int) envp >= 0)
  32     env = *envp;
  33   else
  34     env = (unsigned long int) envp;
  35
  36   /* Reset the rounding mode with the hardware fpcr.  Note that the following
  37      system call is an implied trap barrier for our modification.  */
  38   __asm__ __volatile__ ("excb; mf_fpcr %0" : "=f" (fpcr));
  39   fpcr = (fpcr & ~FPCR_ROUND_MASK) | (env & FPCR_ROUND_MASK);
  40   __asm__ __volatile__ ("mt_fpcr %0" : : "f" (fpcr));
  41
  42   /* Reset the exception status and mask with the kernel's FP code.  */
  43   __ieee_set_fp_control (env & SWCR_ALL_MASK);
  44
  45   /* Success.  */
  46   return 0;
  47 }
  48
  49 #include <shlib-compat.h>
  50 #if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
  51 strong_alias (__fesetenv, __old_fesetenv)
  52 compat_symbol (libm, __old_fesetenv, fesetenv, GLIBC_2_1);
  53 #endif
  54
  55 libm_hidden_ver (__fesetenv, fesetenv)
  56 versioned_symbol (libm, __fesetenv, fesetenv, GLIBC_2_2);